On reading interface3.pdf (July 15, 2015) I see that spaces are not allowed in paths for \file_path_include:n and \file_path_remove:n. To my (mild) surprise I found that \file_if_exist:nTF functioned happily with paths that included spaces, or at least if the current *.tex document was in a directory at the end of a path with spaces, \file_if_exist:nTF was perfectly capable of finding other files in the same directory. I don't doubt there are underlying reasons for the different behaviours, but to someone not steeped in TeX lore, this feels confusing. The \file_path_ functions should also be indifferent to spaces in paths. Andrew Parsloe --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus